Problem: Nadia has lunch at a restaurant and the cost of her meal is $\$50.00$. She would like to leave a $15\%$ tip. What is her total bill including tip?
The tip amount is equal to $15\% \times \$50.00$ We can find the tip by first calculating a $10\%$ tip and a $5\%$ tip, and then adding those two numbers together. To calculate a $10\%$ tip, move the decimal point in $\$50.00$ one place to the left. $10\%$ $\times \$50.00$ $\$5.00$ To calculate a $5\%$ tip, divide the $10\%$ tip amount in half. $5\%$ $\times \$50.00 = $ $\$5.00$ $ \div 2 = $ $\$2.50$ Adding the two amounts together gives us $\$5.00$ $\$2.50 =$ $ \$7.50$ The cost of the meal plus the amount of the tip will equal the total bill amount. $\$50.00 + \$7.50 = $ $\$57.50$ The total cost of the bill is $\$57.50$.